A. Field of the Invention
The invention generally concerns a process for making axially fluorinated-phthalocyanines and their use in photovoltaic applications.
B. Description of Related Art
Hydrogen fluoride (HF) gas and hydrofluoric acid are the primary industrial sources of fluorine or fluoride for a wide range of applications, including the production of fluorinated phthalocyanines (see U.S. Pat. No. 2,227,628). The reason for this is the highly acidic nature of these compounds, which allows for a more efficient chemical reaction to occur. A downside to their use, however, is that they are highly corrosive, which presents significant corrosion challenges to the equipment used in such production processes. To complicate matters, HF is lighter than air and can easily diffuse through porous substances. Further, both HF and hydrochloric acid are highly caustic to human tissue and both acute and chronically toxic, which also complicates the current production processes.
While attempts have been made to use other acids, these attempts also suffer from similar problems—acids in general are caustic in nature. Even further, and due in large part to fluorine's high electronegativity property, HF and hydrofluoric acid is produced as a by-product in such reactions, thereby presenting similar challenges to those mentioned above.